Increased Concentrations of Cardiac Troponin I are Equivalent to Increased Cardiac Troponin T in Identifying Chest Pain Patients at Short-Term Risk of Myocardial Infarction (Letters‪)‬

To the Editor: A recent paper by Christenson et al. (1) presented a comparative analysis of cardiac troponin I (cTnI) and T (cTnT). Their objective was to stratify patients for short-term risk of an acute coronary event on the basis of initial marker concentration as determined within 3.5 h of ischemic symptoms. The authors suggest that cTnT is a better predictor than cTnI on the basis of comparisons of the area under the curve (AUC) of ROC curves for cTnT (AUC = 0.68) and cTnI (AUC = 0.64). However, although weakly significant (P = 0.0375), the 95% confidence interval (CI) for the two areas overlap almost completely (95% CI for cTnI, 0.56-0.72; 95% CI for cTnT, 0.6-0.75). The fact that the samples were not tested for the two analytes simultaneously, but 1 year apart, could easily account for this small difference.